[Triumf-seminars] Special Colloquia on Jan.22-24

[TRIUMF Seminars]

Date/Time: Mon 2018-01-22 at 14:00

Location: Auditorium

Speaker: CMMS Candidate (TBA)

Title: CMMS Candidate Colloquium

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Date/Time: Tue 2018-01-23 at 10:00

Location: Auditorium

Speaker: Sarah Dunsinger (Simon Fraser U)

Title: Depth Resolved Spin Resonance Techniques for Spin Transport Applications

Abstract: The fields of spintronics aims to combine the data storage capabilities of magnetic media with the
data handling capabilities of the semiconductor industry. As such, the controlled manipulation of a
nonequilbrium spin population is required. For example, spin pumping relies on the precession of the
magnetisation induced in a ferromagnet excited by a radio-frequency magnetic field on resonance
(FMR). The magnetisation precession around an effective magnetic field is damped via the emission of
a polarised spin current into the neighbouring normal metal. The flow of this spin current Js across a ferromagnet/normal metal interface may then be detected. Indirect evidence of spin pumping from bulk transport measurements of the charge current Jc induced through the Inverse Spin Hall Effect (ISHE) has been reported in a variety of artificial heterostructures. Our ultimate goal is to look for direct evidence of spin pumping into the nonmagnetic layer of the heterostructures using a depth resolved local probe, measuring the spin diffusion length and spin decoherence timescales.

I will discuss recent investigations using the depth resolved spin resonance techniques Low Energy muSR and beta-detected Nuclear Magnetic Resonance (beta-NMR) of the internal magnetic fields and spin lattice relaxation in simple nonmagnetic metals and semiconductors adjacent to archetypal magnets,
artificial heterostructures of great interest in curiosity driven research but also of relevance for spin transport applications.

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Date/Time: Wed 2018-01-24 at 14:00

Location: Auditorium

Speaker: Karl Johnston

Title: Applying radioactive isotopes to solid state and medical physics: staying relevant in a fast-paced world

Abstract: Having an isotope factory close-by can be a real opportunity to perform innovative experiments in solid state and medical physics. Among the many advantages of radioactivity in solid state physics are its sensitivity and ability to probe local environments in a transparent manner. The ability to pick and choose relevant isotopes for varying chemical systems also opens up many possibilities for unique work in medical physics. However, the pace of nuclear physics and developments in solid state physics are not well-matched: the latter has a considerably faster turnover with "hot" materials changing quickly within a short time frame - especially with regard to the building of nuclear physics infrastructure. I will present recent results, developments and challenges faced at ISOLDE for the applications programme in recent years. Results on applying hyperfine techniques to materials such as topological insulators will be presented as will some of the novel isotopes curre
  ntly being applied to medical physics. The talk will conclude with perspectives on future possibilities at TRIUMF with muon spin resonance, beta-NMR and beyond.